This is what was advertised that the 1.3 patch did.
General stability improvements
Optimize performance for Core 2 Duo CPUs (PC)
Fixed Radiant Story incorrectly filling certain roles
Fixed magic resistances not calculating properly
Fixed issue with placing books on bookshelves inside player purchased homes
Fixed dragon animation issues with saving and loading
Fixed Y-look input to scale correctly with framerate
I honestly cant tell you what in there would cause a drop in framerate.
But 15-30 is about right for that cpu and gpu set. Skyrim is very CPU core clock speed dependent. Take a look at the cpu benchmarks and their core clock speed on skyrim: http://www.tomshardw...ark,3074-9.html
Your CPU is operating at 1.6 ghz which is why you are barely getting 15-30 fps. If your turbo boost technology is on, your cpu shoud jump to 2.8 ghz and deliver more tolerable levels for playing.
To determine if your turbo boost is still working, go to your start menu and type - msconfig - and hit enter.
Click on the third tab which says - services
Click the check box in the bottom left corner that says - hide all microsoft services
You will see displayed all programs currently running in the background on your pc that are not related to your operating system.
You should have one that says - intel turbo boost technology. If it is labeled - running - then we can eliminate that as a cause for your fps drop. If it says - stopped - then that may be why your so slow.
Also, laptops can get very warm and will encounter problems if the gpu gets too warm. Download and install GPU-z. (its free) http://www.techpowerup.com/gpuz/
Click the "sensors" tab and check the box in the bottom corner to continue refreshing...
Start the game and play for a few minutes. Then pause and hit alt+tab and go to the desktop. View your gpu temp on the sensor log. If it is above 80 then that can be a cause of the fps slowdown. This is not likely, but its worthy of checking. Normally you'll see screen issues first.